Thu, 21 Aug 2008 15:06:33 BST CiteULike: Tag fields http://www.citeulike.org/tag/fields CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/weinkauf/article/1703522 <i>(2003)</i> Saddle Connectors - An Approach to Visualizing the Topological Skeleton of Complex 3D Vector Fields Holger Theisel Tino Weinkauf Hans-Christian Hege Hans-Peter Seidel doi:10.1109/VISUAL.2003.1250376 (2003) 2007-09-28T01:52:09-00:00 2003 IEEE Computer Society 3d critical fields points topology vector http://www.citeulike.org/user/weinkauf/article/1703493 <i>Topology-based Methods in Visualization (2007), pp. 51-63.</i><br /><br />Feature Flow Fields (FFF) are an approach to tracking features in a time-dependent vector field v. The main idea is to introduce an appropriate vector field f in space-time, such that a feature tracking in v corresponds to a stream line integration in f. The original approach of feature tracking using FFF requested that the complete vector field v is kept in main memory. Especially for 3D vector fields this may be a serious restriction, since the size of time-dependent vector fields can exceed the main memory of even high-end workstations. We present a modification of the FFF-based tracking approach which works in an out-of-core manner. For an important subclass of all possible FFF-based tracking algorithms we ensure to analyze the data in one sweep while holding only two consecutive time steps in main memory at once. Similar to the original approach, the new modification guarantees the complete feature skeleton to be found. We apply the approach to tracking of critical points in 2D and 3D time-dependent vector fields. Feature Flow Fields in Out-of-Core Settings Tino Weinkauf Holger Theisel Hans-Christian Hege Hans-Peter Seidel doi:10.1007/978-3-540-70823-0_4 Topology-based Methods in Visualization (2007), pp. 51-63. 2007-09-28T01:41:59-00:00 2007 Topology-based Methods in Visualization 51 63 feature fields flow topology http://www.citeulike.org/user/vtanas/article/441081 <i>(1992), pp. 65-77.</i> People Manipulate Objects (but Cultivate Fields): Beyond the Raster-Vector Debate in GIS Helen Couclelis (1992), pp. 65-77. 2005-12-18T19:05:32-00:00 1992 65 77 Springer-Verlag fields gis objects ontology http://www.citeulike.org/user/vlachmore/article/777827 <i>(2003)</i><br /><br />Conditional Random Fields (CRFs) are undirected graphical models, a special case of which correspond to conditionally-trained finite state machines. A key advantage of CRFs is their great flexibility to include a wide variety of arbitrary, non-independent features of the input. Efficiently inducing features of conditional random fields Andrew Mccallum (2003) 2006-07-28T12:59:29-00:00 2003 conditional feature fields induction random selection http://www.citeulike.org/user/vlachmore/article/359689 <i>(2003)</i><br /><br />An approach to semi-supervised learning is proposed that is based on a Gaussian random field model. Labeled and unlabeled data are represented as vertices in a weighted graph, with edge weights encoding the similarity between instances. Semi-supervised learning using Gaussian fields and harmonic functions X Zhu Z Ghahramani J Lafferty (2003) 2005-10-21T09:56:37-00:00 2003 fields gaussian learning random semi-supervised http://www.citeulike.org/user/vlachmore/article/2674017 <i>(2003)</i><br /><br />Coreference analysis, also known as record linkage or identity uncertainty, is a difficult and important problem in natural language processing, databases, citation matching and many other tasks. This paper introduces several discriminative, conditionalprobability models for coreference analysis, all examples of undirected graphical models. Unlike many historical approaches to coreference, the models presented here are relational---they do not assume that pairwise coreference decisions ... Toward conditional models of identity uncertainty with application to proper noun coreference A Mccallum B Wellner (2003) 2008-04-15T16:38:49-00:00 2003 conditional coreference fields noun proper random http://www.citeulike.org/user/vlachmore/article/1290896 <i>pp. 412-418.</i><br /><br />Information Extraction methods can be used to automatically "fill-in" database forms from unstructured data such as Web documents or email. State-of-the-art methods have achieved low error rates but invariably make a number of errors. The goal of an interactive information extraction system is to assist the user in filling in database fields while giving the user confidence in the integrity of the data. The user is presented with an interactive interface that allows both the rapid... Interactive Information Extraction with Constrained Conditional Random Fields Trausti Kristjansson Aron Culotta Paul Viola Andrew Mccallum pp. 412-418. 2007-05-11T22:21:04-00:00 412 418 active active_learning conditional confidence crf entity estimation fields learning named random recognition http://www.citeulike.org/user/vlachmore/article/1185721 <i>Artif. Intell., Vol. 170, No. 14. (October 2006), pp. 1101-1122.</i> Corrective feedback and persistent learning for information extraction Aron Culotta Trausti Kristjansson Andrew Mccallum Paul Viola doi:10.1016/j.artint.2006.08.001 Artif. Intell., Vol. 170, No. 14. (October 2006), pp. 1101-1122. 2007-03-25T01:13:08-00:00 2006 Artif. Intell. 0004-3702 170 14 1101 1122 Elsevier Science Publishers Ltd. conditional extraction feedback fields information random user http://www.citeulike.org/user/vlachmore/article/782591 <i>(2003)</i><br /><br />This paper presents a feature induction method for CRFs. Founded on the principle of constructing only those feature conjunctions that significantly increase loglikelihood, the approach builds on that of Della Pietra et al (1997), but is altered to work with conditional rather than joint probabilities, and with a mean-field approximation and other additional modifications that improve efficiency specifically for a sequence model. In comparison with traditional approaches, automated feature... Early results for named entity recognition with conditional random fields A Mccallum W Li (2003) 2006-08-02T08:58:58-00:00 2003 conditional crf entity feature fields induction named ner random recognition http://www.citeulike.org/user/vlachmore/article/1915444 <i>(2005), pp. 363-370.</i> Incorporating non-local information into information extraction systems by Gibbs sampling Jenny Finkel Trond Grenager Christopher Manning doi:10.3115/1219840.1219885 (2005), pp. 363-370. 2007-11-14T19:16:28-00:00 2005 363 370 Association for Computational Linguistics conditional crf fields ner random skip-chain http://www.citeulike.org/user/vlachmore/article/330532 <i>(2001), pp. 282-289.</i><br /><br />We present conditional random fields, a framework for building probabilistic models to segment and label sequence data. Conditional random fields offer several advantages over hidden Markov models and stochastic grammars for such tasks, including the ability to relax strong independence assumptions made in those models. Conditional random fields also avoid a fundamental limitation of maximum entropy Markov models (MEMMs) and other discriminative Markov models based on directed graphical models, ... Conditional Random Fields: Probabilistic Models for Segmenting and Labeling Sequence Data John Lafferty Andrew Mccallum Fernando Pereira (2001), pp. 282-289. 2005-09-23T08:27:02-00:00 2001 282 289 Morgan Kaufmann, San Francisco, CA conditional crf fields learning machine random http://www.citeulike.org/user/vlachmore/article/1877838 <i>(2003)</i><br /><br />Active and semi-supervised learning are important techniques when labeled data are scarce. We combine the two under a Gaussian random field model. Labeled and unlabeled data are represented as vertices in a weighted graph, with edge weights encoding the similarity between instances. The semi-supervised learning problem is then formulated in terms of a Gaussian random field on this graph, the mean of which is characterized in terms of harmonic functions. Active learning is performed on top of... Combining active learning and semi-supervised learning using gaussian fields and harmonic functions X Zhu J Lafferty Z Ghahramani (2003) 2007-11-07T15:18:28-00:00 2003 active active_learning fields functions gaussian harmonic learning semi-supervised http://www.citeulike.org/user/tyler/article/944855 <i>Geoscience and Remote Sensing, IEEE Transactions on, Vol. 41, No. 3. (2003), pp. 675-686.</i><br /><br />Due to the enormous quantity of radar images acquired by satellites and through shuttle missions, there is an evident need for efficient automatic analysis tools. This paper describes unsupervised classification of radar images in the framework of hidden Markov models and generalized mixture estimation. Hidden Markov chain models, applied to a Hilbert-Peano scan of the image, constitute a fast and robust alternative to hidden Markov random field models for spatial regularization of image analysis problems, even though the latter provide a finer and more intuitive modeling of spatial relationships. We here compare the two approaches and show that they can be combined in a way that conserves their respective advantages. We also describe how the distribution families and parameters of classes with constant or textured radar reflectivity can be determined through generalized mixture estimation. Sample results obtained on real and simulated radar images are presented. Unsupervised classification of radar images using hidden Markov chains and hidden Markov random fields R Fjortoft Y Delignon W Pieczynski M Sigelle F Tupin Geoscience and Remote Sensing, IEEE Transactions on, Vol. 41, No. 3. (2003), pp. 675-686. 2006-11-15T15:55:44-00:00 2003 Geoscience and Remote Sensing, IEEE Transactions on 41 3 675 686 classification fields markov random sar unsupervised http://www.citeulike.org/user/tyler/article/944798 <i>Image Processing, 2001. Proceedings. 2001 International Conference on, Vol. 3 (2001), pp. 1043-1046 vol.3.</i><br /><br />A comparison of the ability to discriminate among distinct regions in synthetic aperture radar (SAR) imagery using textural features based on two different methods is presented. Features are generated from Gauss Markov random field (GMRF) model parameters and from Gabor convolution energies. The discrimination ability is evaluated in terms of misclassification errors resulting from tests performed on a patchwork of different MSTAR clutter regions Gabor vs. GMRF features for SAR imagery classification M Torres-Torriti A Jouan Image Processing, 2001. Proceedings. 2001 International Conference on, Vol. 3 (2001), pp. 1043-1046 vol.3. 2006-11-15T15:46:39-00:00 2001 Image Processing, 2001. Proceedings. 2001 International Conference on 3 1043 1046 vol.3 classification fields gabor gmrf markov random sar http://www.citeulike.org/user/tyler/article/446903 <i>Computer Vision and Pattern Recognition, 1989. Proceedings CVPR '89., IEEE Computer Society Conference on (1989), pp. 61-68.</i><br /><br />A novel algorithm for computing the orientation field for a flowlike texture is presented. The basic idea behind the algorithm is to use an oriented filter, namely the gradient of the Gaussian, and perform manipulations on the resulting gradient vector field. The most important aspect of the algorithm is that it is provably optimal in estimating the local orientations of an oriented texture. An added strength of the algorithm is that it is simpler and has a better signal-to-noise ratio than previous approaches, because it utilizes fewer derivative operations. Also proposed is a measure of coherence which is based on the use of the angle and coherence images as intrinsic images. An analysis of oriented textures requires the computation of these intrinsic images as a first step. In this sense, the computation of the orientation field, resulting in the intrinsic images, is indispensable in the analysis of oriented textures. Results from a number of experiments indicate the usefulness of the angle and coherence intrinsic images Computing oriented texture fields AR Rao BG Schunck Computer Vision and Pattern Recognition, 1989. Proceedings CVPR '89., IEEE Computer Society Conference on (1989), pp. 61-68. 2005-12-21T20:17:15-00:00 1989 Computer Vision and Pattern Recognition, 1989. Proceedings CVPR '89., IEEE Computer Society Conference on 61 68 fields oriented texture http://www.citeulike.org/user/Scis0000002/article/1741439 <i></i><br /><br />This paper considers a number of physical problems, dealing with transformation of the non-radiating electric and magnetic fields between different inertial frames, and analyses an origin of these fields through their sources and the laws of electrostatics and magnetostatics. It has been found that, in all problems of classical electrodynamics dealing either with single space-time transformations or with successive spacetime transformations with collinear velocities, a relationship... Do We Understand the Field Transformations in Classical Electrodynamics? Alexander Kholmetskii 2007-10-08T13:01:02-00:00 fields field-transformations transformations http://www.citeulike.org/user/Scis0000002/article/920532 <i>(1996)</i><br /><br />varieties are the algebraic-geometric analog of manifolds. Clearly affine and projective varieties are examples of abstract varieties, as are open subsets of projective varieties. We drop the modifier "abstract". Definition. An algebraic group is a group (G; Δ) where G is a variety and Δ and inverse are morphisms. The standard examples of algebraic groups are matrix groups. For example consider GLn (K), the invertible n Θ n matrices. As the underlying set we take f(a i;j ; b) 2 ... Model Theory of Fields D Marker M Messmer A Pillay (1996) 2006-10-31T14:55:08-00:00 1996 Springer-Verlag fields field-theories model-theory http://www.citeulike.org/user/Scis0000002/article/2008838 <i>Physics and Chemistry of the Earth, Vol. 31 (2006), pp. 248-257.</i><br /><br />Not Available Coherence of the ULF fields in the seismoactive zone of Japan L Alperovich E Morozov M Hayakawa K Hattori Physics and Chemistry of the Earth, Vol. 31 (2006), pp. 248-257. 2007-11-29T00:52:09-00:00 2006 Physics and Chemistry of the Earth 31 248 257 coherence fields self-interacting ulf http://www.citeulike.org/user/Scis0000002/article/2008821 <i>Cosmic Research, Vol. 37 (March 1999), 113.</i><br /><br />Not Available Measurements of Electromagnetic ULF Fields onboard the Auroral Probe Satellite: the IESP Experiment MM Mogilevsky A Buabdellakh De La Port TV Alexandrova TV Romantsova F Lefeuvre Cosmic Research, Vol. 37 (March 1999), 113. 2007-11-29T00:49:27-00:00 1999 Cosmic Research 37 113 emf fields ulf http://www.citeulike.org/user/Scis0000002/article/2765704 <i>(19 May 2000)</i><br /><br />We propose a distinction between the physical and the mathematical parts of gauge field theories. The main problem we face is to uphold a strong and meaningful criterion of what is physical. We like to call it "Field's dilemma", referring to Hartry Field's nominalist proposal which we consider to be inadaequate. The resolution to the dilemma, we believe, is implicitly provided by the so-called fiber bundle formalism. We shall demonstrate, in detail, that the bundle structure underlying modern quantum and gravitational gauge field theories allows for a genuine distinction between the physically significant and the merely mathematical parts of these theories. Fiber Bundle Gauge Theories and "Field's Dilemma" Yair Guttmann Holger Lyre (19 May 2000) 2008-05-07T13:12:33-00:00 2000 bundels fields forces formal-theories gauge-theories interactions mathematical-structures philosophy-of-physics physical-models physical-structures physical-substrates physical-theories realizability standard-model substrates http://www.citeulike.org/user/Scis0000002/article/2084349 <i>Phys. Rev. D, Vol. 71, No. 10. (May 2005), 104017.</i><br /><br />The periodic standing wave (PSW) method for the binary inspiral of black holes and neutron stars computes exact numerical solutions for periodic standing-wave spacetimes and then extracts approximate solutions of the physical problem, with outgoing waves. The method requires solution of a boundary-value problem with a mixed (hyperbolic and elliptic) character. We present here a new numerical method for such problems, based on three innovations: (i) a coordinate system adapted to the geometry of the problem, (ii) an expansion in multipole moments of these coordinates and a filtering out of higher moments, and (iii) the replacement of the continuum multipole moments with their analogs for a discrete grid. We illustrate the efficiency and accuracy of this method with nonlinear scalar model problems. Finally, we take advantage of the ability of this method to handle highly nonlinear models to demonstrate that the outgoing approximations extracted from the standing-wave solutions are highly accurate even in the presence of strong nonlinearities. Periodic standing-wave approximation: Nonlinear scalar fields, adapted coordinates, and the eigenspectral method B Bromley R Owen RH Price doi:10.1103/PhysRevD.71.104017 Phys. Rev. D, Vol. 71, No. 10. (May 2005), 104017. 2007-12-10T01:58:38-00:00 2005 Phys. Rev. D 71 10 104017 fields general-relativity linearity nonlinearity nonlinear-standing-waves scalar-fields standing-gravitational-waves standing-waves stationary-waves http://www.citeulike.org/user/Scis0000002/article/2081697 <i>(1973)</i><br /><br />Not Available Interplanetary Fields and Plasma: Their Terrestrial Effects on Geomagnetic Storms. MJ Wiskerchen (1973) 2007-12-09T14:29:11-00:00 1973 fields interplanetary plasmas http://www.citeulike.org/user/scis0000001/article/1028388 <i>Probability Theory and Related Fields, Vol. V23, No. 3. (1972), pp. 208-215.</i> The relations between minimal sufficient statistics and minimal sufficient Ï-fields Lothar Rogge doi:10.1007/BF00536560 Probability Theory and Related Fields, Vol. V23, No. 3. (1972), pp. 208-215. 2007-01-06T14:46:42-00:00 1972 Probability Theory and Related Fields V23 3 208 215 fields minimal-sufficient-statistic http://www.citeulike.org/user/rolito/article/1868870 <i>Social Science Information, Vol. 46, No. 4. (1 December 2007), pp. 607-653.</i><br /><br />In the scientific field, agents can choose to contribute to `normal' science, operate within the most highly legitimated avant-garde science (`superstrings', dark matter, etc.) or instead, develop theories within an entirely new theoretical framework, despite the risks which this entails. But the marginality of such theories raises a problem of strategy: those who choose to work on them do so at the expense of their own short-term interests, which would normally be oriented towards occupying a central position in already well-established fields. The theory of scale-relativity (TSR) demonstrates the interest of such a situation: the door is open to new possibilities, but ones that must be built `from scratch'. To pursue work in this direction is more demanding than to choose a project considered risky (due to its inherent difficulty) within the confines of an existing paradigm. On the one hand, TSR proposes to `innovate' and branch out from already widely-accepted conceptual bases, while, on the other hand, it finds itself in a marginal position with respect to the most legitimate avant-garde theories, such as `superstrings'. The case of the TSR thus allows us to study a region of the scientific field which has hardly been explored by a sociology of science that focuses primarily on `extreme' cases: histories of theories which have since been vindicated or spectacular controversies. In 2006, TSR occupies a marginal position within the field of physics. Its status differs widely from `theories' produced outside the field, yet does not correspond to any form of stable, accepted science. As we will show, using a detailed bibliometric analysis, the theory's diffusion throughout the scientific field has been limited albeit real and its results, when sanctioned by an official publication, are rarely taken into account by researchers who are not already TSR collaborators. This isolation within the field reveals conflict and tension between the transformation intended by a theoretical innovation and the norms of standard peer review. As a conclusion, we will compare the strategies of TSR's founder with those of other researchers who at some point in their career have attempted to reorient their scientific trajectory, which in turn reveals the social conditions of these bifurcations that put previously accumulated scientific capital at risk. 10.1177/0539018407082595 De la science normale a la science marginale. Analyse d'une bifurcation de trajectoire scientifique: le cas de la Theorie de la Relativite d'Echelle Vincent Bontems Yves Gingras doi:10.1177/0539018407082595 Social Science Information, Vol. 46, No. 4. (1 December 2007), pp. 607-653. 2007-11-05T14:42:55-00:00 2007 Social Science Information 46 4 607 653 fields marginal normal of science http://www.citeulike.org/user/rodney/article/1747746 <i>Colloid & Polymer Sci, Vol. 255, No. 10. (1977), pp. 980-993.</i><br /><br />Observations of the pair interactions of rigid, conducting spheres suspended in a Newtonian dielectric fluid are described for experiments in which the fluid was subjected to combined simple shear of rate G and uniform electric fields of strength E0 where behaviour is predicted to depend on a parameter f proportional to Esk0/2G. Agreement with theory was excellent for touching spheres which oriented themselves with calculable rates in E0 alone and rotated with calculable periods of rotation in subcritical fields (f<1); in supercritical fields(f?1) the doublets assumed their stable predicted orientations. The trajectories of separated spheres were found to be in good agreement with theory, with capture observed as predicted provided an experimentally determined minimum value, fmin, was exceeded whose value appeared to depend on the surface roughness of the spheres and on their behaviour during dielectric breakdown of the medium when the spheres were close together. After capture spheres appeared to make physical contact. The capture cross-sections were measured and agreed with the theoretical values except below fmin. The significance of the phenomena and the possibilities of employing them for measuring physical properties of dielectric liquids are discussed. © 1977 Dr. Dietrich Steinkopff Verlag. Particle behaviour in shear and electric fields - IX.: Interactions of pairs of conducting spheres (experimental) PA Arp SG Mason doi:10.1007/BF01776205 Colloid & Polymer Sci, Vol. 255, No. 10. (1977), pp. 980-993. 2007-10-10T00:44:37-00:00 1977 Colloid & Polymer Sci 255 10 980 993 Steinkopff-Verlag conducting diffusion doublets electric experiment fields interactions shear spheres http://www.citeulike.org/user/rodney/article/1537220 <i>(2003)</i><br /><br />In this letter I investigate the crystallization of colloidal monolayers and multilayers under convective self-assembly using inclined deposition and under the influence of electric fields. Applying a periodic external field during the crystallization process parallel to the substrate and perpendicular to the growth direction of the layer, the particles order along the field lines and attach as strings to the crystalline interface. The crystalline interface itself melts and freezes periodically due to the applied shear; grain boundaries can be annealed and the formation of large monocrystalline arrays on a very short timescale can be observed. Application of electric fields may thus yield a significantly improved quality of the resulting synthetic opals. Formation of dried colloidal monolayers and multilayers under the influence of electric fields HJ Schope (2003) 2007-08-06T02:56:17-00:00 2003 colloidal dried electric fields monolayer multilayers http://www.citeulike.org/user/pprett/article/1991637 <i>(2004), pp. 42-49.</i> Simple BM25 extension to multiple weighted fields Stephen Robertson Hugo Zaragoza Michael Taylor doi:10.1145/1031171.1031181 (2004), pp. 42-49. 2007-11-27T08:50:33-00:00 2004 42 49 ACM bm25 fields information model probabilistic retrieval http://www.citeulike.org/user/planat/article/116367 <i>(25 February 2005)</i><br /><br />Mutually unbiased bases (MUBs), which are such that the inner product between two vectors in different orthogonal bases is constant equal to the inverse $1/\sqrtd$, with $d$ the dimension of the finite Hilbert space, are becoming more and more studied for applications such as quantum tomography and cryptography, and in relation to entangled states and to the Heisenberg-Weil group of quantum optics. Complete sets of MUBs of cardinality $d+1$ have been derived for prime power dimensions $d=p^m$ using the tools of abstract algebra (Wootters in 1989, Klappenecker in 2003). Presumably, for non prime dimensions the cardinality is much less. The bases can be reinterpreted as quantum phase states, i.e. as eigenvectors of Hermitean phase operators generalizing those introduced by Pegg & Barnett in 1989. The MUB states are related to additive characters of Galois fields (in odd characteristic p) and of Galois rings (in characteristic 2). Quantum Fourier transforms of the components in vectors of the bases define a more general class of MUBs with multiplicative characters and additive ones altogether. We investigate the complementary properties of the above phase operator with respect to the number operator. We also study the phase probability distribution and variance for physical states and find them related to the Gauss sums, which are sums over all elements of the field (or of the ring) of the product of multiplicative and additive characters. Finally we relate the concepts of mutual unbiasedness and maximal entanglement. This allows to use well studied algebraic concepts as efficient tools in our quest of minimal uncertainty in quantum information primitives. Quantum phase uncertainty in mutually unbiased measurements and Gauss sums Michel Planat Haret Rosu (25 February 2005) 2005-03-07T15:14:10-00:00 2005 fields finite number quantum theory http://www.citeulike.org/user/Pilko/article/2878795 <i>Technological Forecasting and Social Change, Vol. In Press, Corrected Proof</i><br /><br />This paper defines the notion of key inventors -- those whose patenting is simultaneously highly productive and also widely cited. By implication, key inventors should be the leaders in any developing new field and we investigate the validity of the notion through an exploration of two emerging technological fields: fuel cell and nanotechnology. The nature of the two groups is compared to discuss the differences between the technological groups. Defining key inventors: A comparison of fuel cell and nanotechnology industries Alan Pilkington Linda Lee Casey Chan Seeram Ramakrishna doi:10.1016/j.techfore.2008.03.015 Technological Forecasting and Social Change, Vol. In Press, Corrected Proof 2008-06-10T08:00:13-00:00 Technological Forecasting and Social Change In Press, Corrected Proof an and any be cell developing emerging exploration field fields fuel in inventors investigate key leaders nanotechnology new notion of should technological the through two validity we http://www.citeulike.org/user/paulschlesinger/article/2604766 <i>The Journal of Chemical Physics, Vol. 128, No. 12. (2008)</i> Biomolecular simulations of membranes: Physical properties from different force fields Shirley Siu Robert Vácha Pavel Jungwirth Rainer Böckmann The Journal of Chemical Physics, Vol. 128, No. 12. (2008) 2008-03-28T03:09:00-00:00 2008 The Journal of Chemical Physics 128 12 AIP fields force phospholipid http://www.citeulike.org/user/olivervoss/article/2005598 <i>J Embryol Exp Morphol, Vol. 91 (February 1986), pp. 101-115.</i><br /><br />There has been a resurgence of interest, recently, in the possible role of neural activity in the ordering of synaptic connections in the lower vertebrate retinotectal system. Blockade of all neural activity, by chronic administration of tetrodotoxin (TTX), during the regeneration of the optic nerve in goldfish has been found to prevent the re-emergence of a fully ordered retinotectal projection. We sought to determine the effects of visual deprivation, a less radical perturbation of neural activity than that produced by TTX, on the initial development of the retinotectal projection. The contralateral visuotectal projection was studied in Xenopus laevis which had been reared in darkness from before the onset of visual function. The projection mapped electrophysiologically at metamorphic climax, or in postmetamorphic juveniles, showed a normal retinotopic topography. The topographic precision of the projection, as revealed by the multiunit receptive field sizes, was the same in light- and dark-reared animals. The laminar distribution, in the superficial neuropil of the optic tectum, of terminals from different classes of retinal ganglion cells was also normal. It is concluded that the specific retinotectal connections underlying these features of the projection are generated by intrinsic developmental processes which do not require visual experience. Among these intrinsic processes might be 'spontaneous' neural activity. Visual deprivation and the maturation of the retinotectal projection in Xenopus laevis. MJ Keating S Grant EA Dawes K Nanchahal J Embryol Exp Morphol, Vol. 91 (February 1986), pp. 101-115. 2007-11-28T15:27:37-00:00 1986 J Embryol Exp Morphol 0022-0752 91 101 115 fields plasticity receptive http://www.citeulike.org/user/NickyWilliams/article/2352998 <i>Rural History, Vol. 18, No. 02. (2007), pp. 217-244.</i><br /><br />State intervention in the United Kingdom's farming industry was necessitated by the problems of the interwar depression and the lead up to World War Two and the emergency wartime food programme. This brought the need for greater bureaucratic machinery which would connect individual farmers and their communities with central government. Crucial from 1939 in this respect was the formation of the County War Agricultural Executive Committees, which became the channels through which English farming was propelled into postwar productivism. Using relatively newly-available documentary material, this article demonstrates the role the committees played in the transmission of national policies down to the local level, their composition and membership. In so doing it also places the economic changes within farming into the vital but under-researched context of their rural social relations during the Second World War. War in the Fields and Villages: The County War Agricultural Committees in England, 1939?45 Brian Short doi:10.1017/S0956793307002166 Rural History, Vol. 18, No. 02. (2007), pp. 217-244. 2008-02-08T10:57:55-00:00 2007 Rural History 18 02 217 244 fields http://www.citeulike.org/user/matttematica/article/1613502 <i></i><br /><br />Springer-Verlag Lecture Notes in Mathematics XVII, pages 243--297. SpringerVerlag, 1981-82. [12] D.J. Aldous. Probability Approximations via the Poisson Clumping Heuristic. Springer-Verlag, New York, 1989. [13] D.J. Aldous. Reversible Markov chains and random walks on graphs, 1994. Unpublished Monograph, Berkeley. [14] R. Aleliunas. Randomized parallel communication. In ACM-SIGOPS Symposium on Principles of Distributed Systems, pages 60--72, 1982. [15] R. Aleliunas, R. M. Karp, R. J. Lipton,... Bibliography Symposium On 2007-09-02T09:49:28-00:00 factoring fields finite large over polynomials http://www.citeulike.org/user/martinthesis/article/2634440 <i>Physical Review Letters, Vol. 75, No. 19. (6 November 1995), 3446.</i><br /><br />Atomic interferences are observed in the micromaser when the inversion of the atoms leaving the cavity is measured while the cavity frequency is scanned across the atomic resonance. The interferences are due to the nonadiabatic mixing of dressed states at the entrance and exit holes of the maser cavity. The interference structures are triangular shaped and approximately equidistant. They are associated with the dynamics of the atom-field interaction; show quantum jumps; and demonstrate bistability of the micromaser field. Atomic Interferometry with the Micromaser G Raithel O Benson H Walther doi:10.1103/PhysRevLett.75.3446 Physical Review Letters, Vol. 75, No. 19. (6 November 1995), 3446. 2008-04-06T09:57:10-00:00 1995 Physical Review Letters 75 19 3446 American Physical Society fields raithel stray http://www.citeulike.org/user/loison/article/411342 <i>Journal of Computational Chemistry, Vol. 25, No. 13. (1 July 2004), pp. 1584-1604.</i><br /><br />Empirical force field-based studies of biological macromolecules are becoming a common tool for investigating their structure-activity relationships at an atomic level of detail. Such studies facilitate interpretation of experimental data and allow for information not readily accessible to experimental methods to be obtained. A large part of the success of empirical force field-based methods is the quality of the force fields combined with the algorithmic advances that allow for more accurate reproduction of experimental observables. Presented is an overview of the issues associated with the development and application of empirical force fields to biomolecular systems. This is followed by a summary of the force fields commonly applied to the different classes of biomolecules; proteins, nucleic acids, lipids, and carbohydrates. In addition, issues associated with computational studies on <IMG SRC="/giflibrary/12/ldquo.gif" BORDER="0">heterogeneous<IMG SRC="/giflibrary/12/rdquo.gif" BORDER="0"> biomolecular systems and the transferability of force fields to a wide range of organic molecules of pharmacological interest are discussed. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1584-1604, 2004 Empirical force fields for biological macromolecules: Overview and issues Alexander Mackerell doi:10.1002/jcc.20082 Journal of Computational Chemistry, Vol. 25, No. 13. (1 July 2004), pp. 1584-1604. 2005-11-29T18:33:52-00:00 2004 Journal of Computational Chemistry 1096-987X 25 13 1584 1604 fields force protein http://www.citeulike.org/user/locatellimp/article/421310 <i>Pervasive Computing, IEEE, Vol. 3, No. 2. (2004), pp. 52-61.</i><br /><br />As computing becomes increasingly pervasive, autonomous computers are going to be embedded in everyday objects in our physical environment. In such scenarios, mobility itself will be pervasive. Mobile users, mobile devices, computer-enabled vehicles, and mobile software components will define a dynamic, networked world in which a large set of autonomous components will interact with each other to orchestrate their activities. We focus on the problem of coordinating autonomous agent's movements in a distributed environment. Orchestrating mobile autonomous agents can take inspiration from the laws of physics. Agent's movements could be driven by locally perceived computational force fields, or cofields, generated by the agents themselves and propagated through an embedded infrastructure. Cofields: a physically inspired approach to motion coordination M Mamei F Zambonelli L Leonardi Pervasive Computing, IEEE, Vol. 3, No. 2. (2004), pp. 52-61. 2005-12-03T17:14:37-00:00 2004 Pervasive Computing, IEEE 3 2 52 61 agents coordination fields http://www.citeulike.org/user/ljaeger/article/2426796 <i>Human Brain Mapping, Vol. 1, No. 3. (1993), pp. 210-220.</i><br /><br />Current approaches to detecting significantly activated regions of cerebral tissue use statistical parametric maps, which are thresholded to render the probability of one or more activated regions of one voxel, or larger, suitably small (e. g., 0.05). We present an approximate analysis giving the probability that one or more activated regions of a specified volume, or larger, could have occurred by chance. These results mean that detecting significant activations no longer depends on a fixed (and high) threshold, but can be effected at any (lower) threshold, in terms of the spatial extent of the activated region. The substantial improvement in sensitivity that ensues is illustrated using a power analysis and a simulated phantom activation study. © 1994 Wiley-Liss, Inc. Assessing the significance of focal activations using their spatial extent KJ Friston KJ Worsley RSJ Frackowiak JC Mazziotta AC Evans doi:10.1002/hbm.460010306 Human Brain Mapping, Vol. 1, No. 3. (1993), pp. 210-220. 2008-02-25T19:17:52-00:00 1993 Human Brain Mapping 1 3 210 220 activation excursion fields functional gaussian imaging mapping parametric set statistical thresholds http://www.citeulike.org/user/larki/article/2536068 <i></i> On the Ramification Theory of Infinite Algebraic Extensions Yukiyosi Kawada 2008-03-15T09:27:20-00:00 algebra fields galois http://www.citeulike.org/user/larki/article/3144058 <i>C. R. Acad. Sci. Paris Sér. I Math., Vol. 315, No. 10. (1992), pp. 1063-1066.</i> Autour d'un problème de Coleman John Boxall C. R. Acad. Sci. Paris Sér. I Math., Vol. 315, No. 10. (1992), pp. 1063-1066. 2008-08-21T09:54:36-00:00 1992 C. R. Acad. Sci. Paris Sér. I Math. 0764-4442 315 10 1063 1066 fields finite http://www.citeulike.org/user/kaniko/article/3144975 <i>Journal of Pragmatics, Vol. 32, No. 10. (September 2000), pp. 1489-1522.</i><br /><br />A theory of action must come to terms with both the details of language use and the way in which the social, cultural, material and sequential structure of the environment where action occurs figure into its organization. In this paper it will be suggested that a primordial site for the analysis of human language, cognition, and action consists of a situation in which multiple participants are attempting to carry out courses of action in concert with each other through talk while attending to both the larger activities that their current actions are ambedded within, and relevant phenomena in their surround. Using as data video recordings of young girls playing hopscotch and archaeologists classifying color, it will be argued that human action is built throught the simultaneous deployment of a range of quite different kinds of semiotic resources. Talk itself contains multiple sign systems with alternative properties. Strips of talk gain their power as social action via their placement within larger sequential structures, encompassing activities, and participation frameworks constituted through displays of mutual orientation made by the actors' bodies. The body is used in a quite different way to perform gesture, again a class of phenomena that encompasses structurally different types of sign systems. Both talk and gesture can index, construe or treat as irrelevant, entities in the participants' surround. Moreover, material structure in the surround, such as graphic fields of various types, can provide semiotic structure without which the constitution of particular kinds of action being invoked through talk would be impossible. In brief it will be argued that the construction of action through talk within situated interaction is accomplished through the temporally unfolding juxtaposition of quite different kinds of semiotic resources, and that moreover through this process the human body is made publicly visible as the site for a range of structurally different kinds of displays implicated in the constitution of the actions of the moment. Action and embodiment within situated human interaction Charles Goodwin doi:10.1016/S0378-2166(99)00096-X Journal of Pragmatics, Vol. 32, No. 10. (September 2000), pp. 1489-1522. 2008-08-21T13:10:22-00:00 2000 Journal of Pragmatics 32 10 1489 1522 action analysis conversation embodiment fields gestures interaction semiotic talk theory http://www.citeulike.org/user/jpcasey/article/1550736 <i>Physical Review Letters, Vol. 96, No. 1. (2006)</i><br /><br />Near-infrared magneto-optical spectroscopy of single-walled carbon nanotubes reveals two absorption peaks with an equal strength at high magnetic fields (>55 T). We show that the peak separation is determined by the Aharonov-Bohm phase due to the tube-threading magnetic flux, which breaks the time-reversal symmetry and lifts the valley degeneracy. This field-induced symmetry breaking thus overcomes the Coulomb-induced intervalley mixing which is predicted to make the lowest exciton state optically inactive (or dark). Excitons in Carbon Nanotubes with Broken Time-Reversal Symmetry S Zaric GN Ostojic J Shaver J Kono O Portugall PH Frings GLJA Rikken M Furis SA Crooker X Wei VC Moore RH Hauge RE Smalley doi:10.1103/PhysRevLett.96.016406 Physical Review Letters, Vol. 96, No. 1. (2006) 2007-08-10T00:05:56-00:00 2006 Physical Review Letters 96 1 APS carbon excitons fields magnetic nanotubes http://www.citeulike.org/user/joshrothman/article/309634 <i>(28 August 2004)</i><br /><br />The philosophy of mind is unique among contemporary philosophical subjects, writes John Searle, "in that all of the most famous and influential theories are false." In Mind, Searle dismantles these famous and influential theories as he presents a vividly written, comprehensive introduction to the mind. Here readers will find one of the world's most eminent thinkers shedding light on the central concern of modern philosophy. Searle begins with a look at the twelve problems of philosophy of mind--which he calls "Descartes and Other Disasters"--problems which he returns to throughout the volume, as he illuminates such topics as the freedom of the will, the actual operation of mental causation, the nature and functioning of the unconscious, the analysis of perception, and the concept of the self. One of the key chapters is on the mind-body problem, which Searle analyzes brilliantly. He argues that all forms of consciousness--from feeling thirsty to wondering how to translate Mallarme--are caused by the behavior of neurons and are realized in the brain system, which is itself composed of neurons. But this does not mean that consciousness is nothing but neuronal behavior. The main point of having the concept of consciousness, Searle points out, is to capture the first person subjective features of the phenomenon and this point is lost if we redefine consciousness in third person objective terms. Described as a "dragonslayer by temperament," John Searle offers here a refreshingly direct and open discussion of philosophy, one that skewers accepted wisdom even as it offers striking new insights into the nature of consciousness and the mind. Mind: A Brief Introduction (Fundamentals of Philosophy) John Searle (28 August 2004) 2005-09-01T02:52:06-00:00 2004 Oxford University Press consciousness fields neuroscience philosophy science searle http://www.citeulike.org/user/higueruelo/article/2256566 <i>Biochemistry (19 January 2008)</i><br /><br />Abstract: Vibrational Stark effect spectroscopy was used to measure electrostatic fields in the hydrophobic region of the active site of human aldose reductase (hALR2). A new hALR2 inhibitor was designed and synthesized that contains a nitrile probe with a Stark tuning rate of 0.77 cm-1/(MV/cm). Mutations to amino acid residues in the vicinity of the nitrile functional group were selected based on electrostatics calculations, possible complications from hydrogen bonds near the nitrile, and comparison with the active site of human aldehyde reductase, whose structure is very similar. Changes in the absorption energy of the nitrile probe when bound to those mutated proteins were then used to quantify perturbations to the protein's electrostatic field. Electrostatic field changes as large as -10 MV/cm were observed. Measured electrostatic fields were compared to predictions based on continuum electrostatics calculations, revealing that substantial modifications to the calculation strategy are necessary. The effects of hydrogen bonding of amino acid side chains to the nitrile probe are considered, and applications of vibrational Stark effect spectroscopy to investigations of ligand binding and biological function are discussed. Electrostatic Fields Near the Active Site of Human Aldose Reductase: 1. New Inhibitors and Vibrational Stark Effect Measurements LJ Webb SG Boxer doi:10.1021/bi701708u Biochemistry (19 January 2008) 2008-01-19T12:47:29-00:00 2008 Biochemistry 2008 fields halr2 sm-prot stark xf http://www.citeulike.org/user/harshad12/article/2762821 <i>J. Phys. Chem. A, Vol. 111, No. 37. (20 September 2007), pp. 9111-9121.</i><br /><br />Abstract: The influence of a uniform static external electric field on some aliphatic and aromatic molecular species is studied within the density functional theory (DFT) employing the 6-311++G(2d,2p) basis set with B3LYP exchange-correlation prescription. The electric field perturbs the molecular geometry but drastically alters the dipole moments and engenders, to a varying degree, the molecular vibrational Stark effect, i.e., shifts in the infrared (IR) vibrational frequencies accompanied by spectral intensity redistribution. For polar molecules, significant negative ("red") and positive ("blue") frequency shifts are observed for field orientations both parallel and antiparallel to their permanent dipole moments. Further, a selective reordering of frontier orbitals is observed to be brought about by moderately intense fields. In particular, molecules having a lowest unoccupied molecular orbital (LUMO) with predominant character possess a threshold field beyond which energy gap between the highest occupied molecular orbital (HOMO) and LUMO diminishes rapidly. A time-dependent (TD) DFT analysis reveals that an increase in the applied field strength by and large increases the excitation energies corresponding to significant electronic transitions among frontier MOs with a concomitant decrease in their oscillator strengths. Electric Field Effects on Aromatic and Aliphatic Hydrocarbons: A Density-Functional Study D Rai H Joshi AD Kulkarni SP Gejji RK Pathak doi:10.1021/jp074051v J. Phys. Chem. A, Vol. 111, No. 37. (20 September 2007), pp. 9111-9121. 2008-05-06T20:15:37-00:00 2007 J. Phys. Chem. A 111 37 9111 9121 aliphatic amphiphiles aromatic benzene calculations charge-transfer cluster compounds conventions crystalstructure crystalviolet defects dft dynamics electricdipole excited excitedstate experiment experiments femtosecond fields fluorescence force gaussian hyperpolarizability hyperpoparizability initio ions local_fields molecules optical organic polarisability simulation simulations small water http://www.citeulike.org/user/hallman/article/3097296 <i>(6 Aug 2008)</i><br /><br />We performed cosmological, magneto-hydrodynamical simulations to follow the evolution of magnetic fields in galaxy clusters, exploring the possibility that the origin of the magnetic seed fields are galactic outflows during the star-burst phase of galactic evolution. To do this we coupled a semi-analytical model for magnetized galactic winds as suggested by Bertone et.al. (2006) to our cosmological simulation. We find that the strength and structure of magnetic fields observed in galaxy clusters are well reproduced for a wide range of model parameters for the magnetized, galactic winds and do only weakly depend on the exact magnetic structure within the assumed galactic outflows. Although the evolution of a primordial magnetic seed field shows no significant differences to that of galaxy clusters fields from previous studies, we find that the magnetic field pollution in the diffuse medium within filaments is below the level predicted by scenarios with pure primordial magnetic seed field. We therefore conclude that magnetized galactic outflows and their subsequent evolution within the intra-cluster medium can fully account for the observed magnetic fields in galaxy clusters. Our findings also suggest that measuring cosmological magnetic fields in low-density environments such as filaments is much more useful than observing cluster magnetic fields to infer their possible origin. Cluster Magnetic Fields from Galactic Outflows J Donnert K Dolag H Lesch E M&#xfc;ller (6 Aug 2008) 2008-08-08T03:12:58-00:00 2008 fields magnetic outflows simulations http://www.citeulike.org/group/566/article/441908 <i>Circ Res, Vol. 66, No. 5. (May 1990), pp. 1190-1203.</i><br /><br />During internal defibrillation, potential gradients greater than 100 V/cm occur near defibrillation electrodes. Such strong fields may cause deleterious effects, including arrhythmias. This study determined 1) the effects of such strong fields on the propagation of activation and 2) whether these effects were different for monophasic and biphasic shocks. Voltages and potential gradients during the shock, as well as activation sequences before and after the shock, were mapped from 117 epicardial electrodes placed over a 3 x 3-cm area on the right ventricle in six dogs. Pacing at a cycle length of 350 msec was given from a long narrow electrode on the right side of the mapped area to generate parallel activation isochrones. A monophasic shock, 10 msec in duration, or a biphasic shock with both phases 5 msec in duration was delivered 300 msec after the last paced stimulus via a mesh electrode on the left side of the mapped area as the cathode, with the anode on the right atrium. Shocks of 70-850 V were given, and the potential gradient and current density at each recording electrode were calculated from the measured potentials and fiber orientation by using a finite element method. Pacing was resumed 200 msec after the shock, and activation sequences were mapped for up to 5 minutes. Potential gradients ranged from 1 to 189 V/cm with high fields on the left side and low fields on the right side of the mapped area. Where the potential gradient was weak, the first activation sequence after the shock was similar to that before the shock, but activation blocked without conducting into areas where the gradient was greater than 64 +/- 4 (mean +/- SD) V/cm for monophasic and greater than 71 +/- 6 V/cm for biphasic shocks. These values are significantly different (p less than 0.003). The higher the potential gradient, the longer was the duration of block before conduction returned. Block duration, however, was generally shorter for biphasic than for monophasic waveforms of the same field strength. In conclusion, conduction block can follow either waveform, but biphasic waveforms cause less block than monophasic waveforms. This effect may partially explain the increased defibrillation efficacy of biphasic shocks. Conduction disturbances caused by high current density electric fields. S Yabe WM Smith JP Daubert PD Wolf DL Rollins RE Ideker Circ Res, Vol. 66, No. 5. (May 1990), pp. 1190-1203. 2005-12-19T17:37:00-00:00 1990 Circ Res 0009-7330 66 5 1190 1203 conduction current_density electrophysiology fields heart myocardium http://www.citeulike.org/group/48/article/422892 <i>(2 Dec 2005)</i><br /><br />Deterministic dynamical models are discussed which can be described in quantum mechanical terms. -- In particular, a local quantum field theory is presented which is a supersymmetric classical model. The Hilbert space approach of Koopman and von Neumann is used to study the classical evolution of an ensemble of such systems. Its Liouville operator is decomposed into two contributions, with positive and negative spectrum, respectively. The unstable negative part is eliminated by a constraint on physical states, which is invariant under the Hamiltonian flow. Thus, choosing suitable variables, the classical Liouville equation becomes a functional Schroedinger equation of a genuine quantum field theory. -- We briefly mention an U(1) gauge theory with “varying alpha” or dilaton coupling where a corresponding quantized theory emerges in the phase space approach. It is energy-parity symmetric and, therefore, a prototype of a model in which the cosmological constant is protected by a symmetry. Deterministic models of quantum fields Hans-Thomas Elze (2 Dec 2005) 2005-12-05T19:22:42-00:00 2005 fields quantum http://www.citeulike.org/group/48/article/71317 <i>Journal of Symbolic Computation, Vol. 29, No. 6. (2000), pp. 879-889.</i><br /><br />this paper follows. Algorithms for Exponentiation in Finite Fields Shuhong Gao JVz Joachim Daniel Panario Victor Shoup Journal of Symbolic Computation, Vol. 29, No. 6. (2000), pp. 879-889. 2004-12-30T12:34:14-00:00 2000 Journal of Symbolic Computation 29 6 879 889 algorithm exponentiation fields finite http://www.citeulike.org/group/2192/article/1127791 <i>The European Physical Journal C - Particles and Fields, Vol. 49, No. 3. (February 2007), pp. 685-696.</i> Chiral symmetry and diffractive neutral pion photo- and electroproduction Ewerz Nachtmann doi:10.1140/epjc/s10052-006-0082-9 The European Physical Journal C - Particles and Fields, Vol. 49, No. 3. (February 2007), pp. 685-696. 2007-02-27T17:44:34-00:00 2007 The European Physical Journal C - Particles and Fields 1434-6044 49 3 685 696 Springer 2007 abs fields nread physics qm theoretical-physics http://www.citeulike.org/group/2192/article/1127788 <i>The European Physical Journal C - Particles and Fields, Vol. 49, No. 3. (February 2007), pp. 709-719.</i> Quark and pion condensation in a chromomagnetic background field Ebert Klimenko Zhukovsky Fedotov doi:10.1140/epjc/s10052-006-0143-0 The European Physical Journal C - Particles and Fields, Vol. 49, No. 3. (February 2007), pp. 709-719. 2007-02-27T17:44:31-00:00 2007 The European Physical Journal C - Particles and Fields 1434-6044 49 3 709 719 Springer 2007 abs chromodynamics fields magnetism nread physics pion quark theoretical-physics